Preheat oven to 350 and line a 13x9 pan with tin foil extended over sides. Grease tin foil.
FOR CRUST: Combine cookie mix and flour, cut in butter until mixture resembles fine crumbs. Press into greased pan and bake for about 15 minutes or until edges are lightly browned (mine never quite made it to brown, so I just gave up after about 18 minutes, they turned out fine).
MIDDLE LAYER: (make this while crust is baking) Whisk together egg yolks, sweetened, condensed milk, and peppermint extract (I just did it for about a minute until everything looked fully combined) Stir in the crushed peppermints. Once the crust is done, pour mixture over it as carefully and evenly as possible and bake for about 20-25 minutes. Once done, let cool on counter for about an hour and chill in fridge for another 30 minutes (it's a long process but SO GOOD! I promise!).
WHITE CHOCOLATE GANACHE: Heat heavy whipping cream just to boiling, remove from heat and add white chocolate chips DON'T STIR YET! Let sit for five minutes, stir together until smooth (I assume if you use really good white chocolate this process will be a lot easier, but my cheap chips were stubborn so I had to stir for a long time to get all the little suckers melted together) Pour over cooled bars, spread evenly. Put back in fridge for another hour (I took them out after about 40 minutes because I couldn't stand it anymore!) until set. Cut into bars (makes about 36).